The present disclosure relates to a multilayer ceramic electronic component to be embedded in a board and a printed circuit board having a multilayer ceramic electronic component embedded therein.
As electronic circuits have become highly densified and highly integrated, a mounting space for passive elements mounted on a printed circuit board (PCB) has become insufficient. In order to solve this problem, ongoing efforts have been made to implement components able to be installed within a board, such as embedded devices. In particular, various methods have been proposed for installing a multilayer ceramic electronic component used as a capacitive component within a board.
As one of a variety of methods of installing a multilayer ceramic electronic component within a board, the same dielectric material used for a multilayer ceramic electronic component is used as a material for a board and a copper wiring, or the like, is used as an electrode. Other methods for implementing an embedded multilayer ceramic electronic component include forming an embedded multilayer ceramic electronic component by forming a polymer sheet having high-k dielectrics or a dielectric thin film within a board, installing a multilayer ceramic electronic component within a board, and the like.
In general, a multilayer ceramic electronic component includes a plurality of dielectric layers made of a ceramic material and internal electrodes interposed therebetween. By disposing a multilayer ceramic electronic component within a board, an embedded multilayer ceramic electronic component having high capacitance may be implemented.
In order to manufacture a printed circuit board (PCB) including an embedded multilayer ceramic electronic component, a multilayer ceramic electronic component may be inserted into a core board, and via holes are required to be formed in an upper stacked plate and a lower stacked plate by using a laser in order to connect board wirings and external electrodes of the multilayer ceramic electronic component. Laser beam machining, however, considerably increases manufacturing costs of a PCB.
Meanwhile, an embedded multilayer ceramic electronic component is installed in a core part within a board, so a nickel/tin (Ni/Sn) plated layer on external electrodes thereof is not required, unlike a general multilayer ceramic electronic component mounted on a surface of a board.
Namely, since external electrodes of an embedded multilayer ceramic electronic component are electrically connected to a circuit within a board through a via made of a copper (Cu) material, a copper (Cu) layer, rather than a nickel/tin (Ni/Sn) layer, is required to be formed on the external electrodes.
In general, external electrodes may include copper (Cu) as a main ingredient, but since external electrodes include glass, a component included in the glass may absorb a laser in the event of laser beam machining to form a via within a board, making it difficult to adjust a process depth of the via.
For this reason, a copper (Cu) plated layer is separately formed on external electrodes of an embedded multilayer ceramic electronic component.
However, forming the copper (Cu) plated layer increases cost and still causes the problem of degradation of reliability due to infiltration of a plating solution, and a solution thereto is still needed.